U.S. Pat. No. 4,059,644 to Cannell discloses a method for producing high-energy fuels by thermal (non-catalytic) reaction of a mixture of cyclopentadiene dimer and methyl cyclopentadiene dimer at 150.degree.-220.degree. C., and subsequent hydrogenation of the olefinic unsaturation in the oligomeric product mixture.
U.S. Pa. No. 4,401,837 to Burdette et al. discloses a method for synthesizing cyclopentadiene trimers and higher molecular weight oligomers from cyclopentadiene dimer via thermal (non-catalytic) Dieis-Alder reactions. The trimer fraction of the intermediate oligomeric product is then treated in the presence of a hydrogenation catalyst to saturate the olefinic bonds. While the initial thermal reaction produces trimers, tetramers, and pentamers, only the trimer fraction is used for the high density fuel product. After the initial reaction, the mixture is hydrogenated to saturate the olefinic bonds and distilled to recover the C.sub.15 trimer. Thus the formation of higher molecular weight oligomers (C.sub.20+) represents yield loss. The trimer, after hydrogenation, is a solid at room temperature with a melting point of +49.degree. C. This trimer is then dissolved in methylene chloride and isomerized at 0.degree.-20.degree. C. using aluminum chloride as catalyst. The isomerized product is subsequently recovered by distillation.
These prior art processes produce a normally solid intermediate product (after hydrogenation) which must then be isomerized to form a normally liquid product. Further, the prior art processes sacrifice yield because only a portion of the oligomerized intermediate product (the trimer) is used for upgrading to the final high density fuel product. Thus it would be desirable to provide a process which avoids the costly isomerization step. Further, it would be desirable to provide a process which enhances yield by incorporating substantially all of the oligomerized intermediate product into the final high density fuel product.